1. Introduction The effects of human recreation on wildlife populations have been of particular interest due to the rapid increase in outdoor recreational activities in the last few decades. Humans can affect turtles in various ways such as: Vehicle accidents from RV’s, cars, or motorized boats (Bowen & Janzen, 2008) Boating activity, which may influence behavior, prey movement, degrade habitat quality, or cause avoidance of feeding or breeding areas (Richardson et al., 1995) Destroyed nests from recreational equipment (Bennett, 2012) Shifting/trampling of nests (Blood & Macartney, 1998) Predation by raccoons, foxes, and skunks, whose numbers have increased, as a result of human waste/trash (Garber & Burger, 1995) Capturing for pets (Blood & Macartney, 1998) Handling by people (Garber & Burger, 1995) Very few studies have examined the impact of boating activity on freshwater turtles, even though many are species at risk (Bulte et al., 2009). Biologists in eastern North America are reporting significant declines in turtle populations, although it is unknown which factors are most important (Garber & Burger, 1995). Red-bellied turtles (Pseudemys rubriventris) are specifically of interest due to their threatened status in Pennsylvania. Determining if human activities are impacting the behaviors of turtle species in Lake Marburg is important for obtaining a better understanding of this relationship. The effect of human recreation on aquatic basking turtle populations at Lake Marburg (Hanover, Pa) Marissa Schneider and Dr. Jessica Nolan, Department of Biology, York College Objective To observe and monitor aquatic turtle basking platforms and traps during different levels of human recreation at Lake Marburg. Hypotheses (1) The higher the level of human activity, the fewer number of turtles will be caught in the traps. (2) The more activity present in the coves, the fewer number of turtles will be basking. Methods Sampling took place in June and July 2013 within Lake Marburg during 3 different levels of overall activity of the park: Mid-week: Low activity sample (n=6) Weekend: Medium activity sample (n=6) Codorus Blast Festival: High activity sample (n=6) Activity samples were determined by average park attendance numbers, given by communication with the park manager: Mid-week: ~1,500 people/day Weekend: ~5,000 people/day Codorus Blast: ~15,000 people/day Six coves within the lake were used in sampling: Sailboat, Chapel, Dubs, Black Rock Launch, Black Rock Flats, and Hoff Road. Traps baited with canned sardines were placed in lake to capture turtles 24 hours before being checked. The number of turtles basking and number of disturbances, which included motorboats, kayaks, and vehicles, were observed and recorded from a distance on shore and via kayak, which allowed for a more closer look, for approximately 15 minutes. Turtle traps were retrieved and the number of turtles caught in the trap were recorded. Turtles were immediately released to minimize impact. Results: Traps Results: Basking Multiple Regression Table Future Study Tracking movements of turtles within coves with and without disturbance Do turtles swim away or hide when boat is present? Focus more on red-bellied turtles Figure 5. Representation of 2 painted turtle movements with disturbance present, tracked on July 27, 2013. Conclusions The number of turtles caught in traps was not impacted by the various activity levels. Lake disturbances (boats) did not effect turtle basking habits. Basking numbers varied throughout the six coves. Mostly observed/caught painted turtles. More research should be conducted to better understand turtle activity and behavior when human recreation is present, especially in red-belled turtles. Literature Cited Baldwin, E. A., Marchand, M. N., and Litvaitis, J. A. 2004. Terrestrial habitat use by nesting painted turtles in landscapes with different levels of fragmentation. Northeastern Naturalist 11: 41-48. Blood, D.A. and Macartney, M. 1998. Painted turtle: The habitats occupied by this turtle are same locations favoured for human settlement. Available from: http://www.env.gov.bc.ca/wld/documens/pturtle.pdf. Accessed 29 Jan 2014. Bowen, K.D. and Janzen, F.J. 2008. Human recreation and the nesting ecology of a freshwater turtle (Chrysemys picta). Chelonian Conservation and Biology 7:95-100. Bulte, G., Carriere, M.A., and Blouin-Demers, G. 2009. Impact of recreational power boating on two populations of northern map turtles (Graptemys geographical). Aquatic Conservation: Marine and Freshwater Ecosystems 20:31-38 Garber, S.D. and Burger, J. 1995. A 20-yr study documenting the relationship between turtle decline and human recreation. Ecological Applications 5:1151-1162. Moore, M.J.C. and Seigel, R.A. 2006. No place to nest or bask: Effects of human disturbance on the nesting and basking habits of yellow-blotched map turtles (Graptemys flavimaculata). Biological Conservation 30:386-393. Acknowledgements I would like to thank my mentor, Dr. Nolan for all her time and effort throughout this study. Her continuous support and encouragement was truly appreciated. I would like to thank the Pennsylvania Boat and Fish Commission and Codorus State Park to allowing research to be done at Lake Marburg. Multiple Regression Analysis Constant = Number of turtles basking Overall multiple regression was not significant (p=0.0798). Significant differences between coves, but not in response to human activity.